First human embryos edited in the USA. Here's why it's problematic

Shoukhrat Mitalipov is the first U.S.-based scientist known to have edited the DNA of human embryos.		
	OHSU  Kristyna Wentz-Graff

Shoukhrat Mitalipov is the first U.S.-based scientist known to have edited the DNA of human embryos. OHSU Kristyna Wentz-Graff

The researchers from the Institute for Basic Science (IBS) and Oregon Health and Science University (OHSU) used the groundbreaking gene-editing tool called CRISPR-Cas9 to fix the DNA piece that causes a common genetic heart disease known as hypertrophic cardiomyopathy, the IBS said.

An global team of scientists has successfully edited of the genes of a viable human embryo, correcting a mutation that can cause the heart condition hypertrophic cardiomyopathy.

In particular, the novel technique can target a disease known as hypertrophic cardiomyopathy, a heart failure condition that causes sudden death in both genders.

Genetic engineering has always been a sensitive issue, but the scientists from Oregon Health and Science University in Portland said they believe they have broken new ground in the prevention of inherited disease by correcting deficient genes.

It marked the first time scientists had successfully tested the gene-editing method on donated clinical-quality human eggs, OHSU said. The consequences of the research may not be felt for quite a while yet as clinical trials remain a long way off, and are in fact now impermissible under federal law.

During the OHSU experiment, the CRISPR-Cas9 tool cut out the bad gene - and then the embryo replaced it with a copy of the good gene it had inherited from the mother.

The experiments were privately funded; USA tax dollars aren't allowed for embryo research.

Using IVF techniques, the researchers injected the best-performing gene-editing components into healthy donor eggs newly fertilized with the donor's sperm. Technology Review explained, "while scientists say the approach could one day be used to avoid genetic diseases, some have raised concerns that it could lead to 'designer babies.' "And, some have even called CRISPR a potential "weapon of mass destruction. In other words, making changes to sperm, to eggs, or to early embryos as a way of potentially addressing diseases - inheritable diseases and so forth".

After CRISPR cut out those bad segments, the embryo itself repaired the cut. Natural DNA-repair mechanisms in the cell follow up by filling in the missing pieces.

Unlike research groups before them - which worked on embryos that were not capable of ever becoming a baby - this study involved the creation of healthy human embryos specifically for research purposes.

Additionally, we're at least decades away from having gene therapy techniques like this one become the norm. In addition, there are thousands of genetic diseases wherein the same procedure could be applied.

Unlike past experiments that attempted CRISPR days after embryos had developed, this one did it at the time of fertilization. That led to a patchwork, or mosaic, embryo with edited and unedited cells (top, right).

Furthermore, to be ethical, any applications or experiments utilizing CRISPR or other gene editing technology can not use any other methods in its process which are themselves intrinsically immoral, Fr.Pacholczyk said.

The goal: to cut the defective DNA to bring about its fix. Thus some of the embryos carried the DNA error, and some were "healthy". L. No. 114-113), "prohibits use of federal funds by the FDA to "acknowledge receipt of a submission to initiate clinical trials of a drug or biological product" involving 'research in which a human embryo is intentionally created or modified to include a heritable genetic modification'".

"Human Genome Editing: Science, Ethics and Governance" was published by the National Academy of Science, a publication that two years to produce.

In fact, Mitalipov said the research should offer critics some reassurance: If embryos prefer self-repair, it would be extremely hard to add traits for "designer babies" rather than just eliminate disease.

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